The initial symptoms of CFS are identical to Hypoxia, and
the recent findings of severe loss of oxygen capacity (see
VO2-Max) in CFS patients leads to the conclusion that they are hypoxia
(at sea level) symptoms caused by a change of pH in the blood,
coagulation (slowing down the blood flow) and destruction of red blood
cells.

The term hypoxia includes the following:

Acute Mountain Sickness (AMS),

High Altitude Pulmonary Edema (HAPE) and

Cerebral Edema (HACE).

There are two processes occurring with the above:

decrease of oxygen

to the body

loss of air pressure to the lungs.

The latter does not occur with CFIDS, the former does
(because of thick blood or other conditions)- thus all lung/breathing symptoms
are omitted from the discussion below. There are no laboratory tests to identify
AMS

Altitude Sickness Symptoms

The typical symptoms are (% for 8000'):

mild headache (70%)

a severe headache which fails to respond to any normal

treatment (7%)

sleep disturbance, insomnia ( 30%)

weakness, fatigue (30%)

increased thirst

nausea (5%)

loss of appetite, anorexia (5%)

dizziness (20%),

apathy

flu like symptoms in the absence of a fever or only a very

low grade fever

noticeable symptoms of slurred speech,

loss of decision making skills,

loss of coordination and vision

Clinical Determination

At altitudes over 2400m / 8000 ft, the diagnosis of
AMS is based on a headache plus at least

one of the following symptoms:

GI upset (loss of appetite, nausea, vomiting)

fatigue/weakness

dizziness/light-headedness

insomnia (more than just the usual frequent waking)

HACE will have symptoms of AMS plus either gait ataxia or mental
status changes, or will have both gait ataxia and mental status changes
regardless of AMS symptoms. ... use a simple tandem-gait test: asking the
patient to walk heel-toe along a straight line..., they should be able to
perform this test without difficulty. If they struggle to stay on the line, fall
off it, or are unable to walk without assistance, they fail and are presumed to
have HACE.

Side effects are reduced by drugs that increase the rate of
respiration (thus not likely to be effective for CFS).